Method and apparatus for constructing and setting trench cribbing



June 13, 1961 2,987,890

O. J. DRUML METHOD AND APPARATUS FOR CONSTRUCTING AND SETTING TRENCH CRIBBING Filed July 19, 1957 MM l r A I! W1 1 II :1 l 12 W l INVENTOR.

OSCAR i. DRUML BY' 47 THE NE Y5 United States Patent 2,987 890 METHOD AND APPARATlJS FOR 'CONSTRUCTING AND SETTING TRENCH CRIBBING Oscar 1!. Drum], 3600 N. Pilgrim Road, Brookfield, Wis. Filed July 19, 1957, Ser. No. 672,908 4 Claims. (Cl. 61-41) This invention relates to a method and apparatus for constructing and setting trench cribbing to shore up the walls of a trench dug in the earth for receiving sewer pipe and the like.

Heretofore, it has generally been the custom when ex- A present threat of a cave-in makes this work extremely hazardous. The method and apparatus of this invention are intended to eliminate this hazard to the workmen and greatly increase the speed of assembly of the trench cribbing to reduce the cost of the shoring-up operation.

According to this invention, apparatus comprising separable frame units are employed for the assembly of the cribbing. Each frame unit comprises transversely spaced vertical members connected by one or more adjustable tie rods and provided with a plurality of vertically spaced transversely aligned bracket means or other suitable means adapted to receive and support longitudinally extending wooden beams or stringers. The frame units are employed in pairs and are longitudinally spaced and aligned to place the bracket means on the respective units in longitudinally aligned relation. The section of trench cribbing comprising horizontal stringers, cross-braces and vertical sheathing are assembled to the spaced frame units at ground level with the aligned bracket means receiving the stringers to support the section. Means are provided whereby the frame units to which a section of cribbing has been assembled may be lifted for placement in the trench and whereby the frame units are removed after the section of cribbing is secured in the trench.

Briefly, the method of assembling and setting the trench cribbing entails placing a pair of frame units having vertically spaced and transversely aligned bracket means in longitudinally spaced relation at ground level so as to place the bracket means on the respective units in longitudinal alignment. Assembling a plurality of longitudinally extending beams or stringers to the aligned bracket means of the spaced frame units. Securing suitable crossbraces between the transversely spaced stringers and vertical sheathing to the stringers outwardly of the frame units to complete the assembly of a section of the trench cribbing. Moving the frame units together with the cribbing section into position within the trench, and thereafter removing the frame units from the trench for employment in the assembly of a subsequent section of trench cribbing.

The drawings furnished herewith illustrate the best mode of carrying out the invention as presently contemplated and set forth hereinafter.

In the drawings:

FIGURE 1 is a perspective view with parts broken away showing a section of trench cribbing partially as sembled at ground level to the frame units of this invention;

FIGURE 2 is a perspective view with parts broken away showing a section of the assembled cribbing after it has been set in a trench and before the removal of the frame units; and

FIG. 3 is an elevational view showing a frame unit.

In the drawings there is shown a pair of longitudinally spaced frame units 1 to which a section of trench cribbing is assembled at ground level.

Each frame unit 1 comprises a pair of transversely spaced vertical members 2 having respectively a plurality of vertically spaced bracket members 3 or other suitable means which open outwardly of the frame unit and are adapted to receive and support a horizontally extending beam or stringer 4. The bracket members 3 on each vertical member 2 are transversely aligned with the corresponding bracket members on the other of the vertical members 2 and a transversely extending adjustable jack screw 5 extends between the aligned bracket members.

The jack screws 5 comprise a threaded member 6 secured to the inside of one bracket member 3 and coupled with an internally threaded member 7 mounted rotatably to the inside of the correspondingly aligned bracket member. Lever means 8 are provided on the rotatable member 7 whereby threaded engagement between members 6 and 7 may be varied to space the vertical members 2 along with the brackets 3 transversely in accordance with the trench width.

Each vertical member 2 of frame unit 1 is provided with a ring member 9 at the upper end thereof which is adapted to receive cable means 10 or the like whereby the frame unit together with a section of cribbing may be moved from the location of assemblage to the trench as will be described more fully hereinafter.

In the assemblage of a section of trench cribbing, two or more of the frame units 1 are disposed in longitudinally spaced and aligned relation to place corresponding brackets 3 in longitudinally aligned relation to receive a plurality of longitudinal stringers 4 between the frame units. Assembled to the spaced frame units 1 in this manners, stringers 4 will be in substantial alignment vertically and transversely to support the aligned frame units in an upright position.

According to the method of this invention, a section of trench cribbing is assembled at ground level generally adjacent to the trench site. Initially a pair of frame units 1, as shown in the drawings, or more, are placed in an upright position in longitudinally aligned relation. The distance between the vertical members 2 of each frame unit having been properly adjusted to correspond to the trench width, longitudinally extending stringers 4 having a length corresponding to that of a section of trench cribbing are assembled to the aligned bracket members 3 adapted to receive them. A plurality of cross-braces 11 of appropriate width are then secured between the transversely spaced and aligned stringers 4 and vertical sheathing 12 of appropriate height, which may comprise separable boards as shown in the drawings, is secured to the vertically spaced stringers 4 outwardly from the frame units to complete the cribbing assembly.

After assembly of the cribbing section at ground level, the section is picked up as a whole together with the frame units 1 by means of a crane or the like, not shown, and as represented by the hook member 13 engaging cable means 10, and is disposed in the trench. After the cribbing section is secured in place the separable frame units 1 may be loosened from the section by means of the screw jacks 7 and removed from the trench to provide frame units for the assembly and setting of subsequent sections of trench cribbing.

The ground level assemblage of trench cribbing contemplated by this invention provides a method wherein the cribbing materials can be more readily accessible and handled with relative ease to increase the speed of as sembly and therefore reduce the cost of shoring-up opera tions. Furthermore, the threat of cave-ins to the lives of the workmen are substantially eliminated since themethod provides that the cribbing section is placed into the trench before workmen are required to enter the trench.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

Iclaim:

1. A frame assemblage for constructing a section of trench cribbing for shoring up the walls of a trench, comprising separable frame units disposed in longitudinally spaced and aligned relation and adapted to be connected by trench cribbing members, each of said frame units comprising a pair of vertical members, adjustable means connecting said members and supporting same in transversely spaced relation corresponding generally to the Width of the trench, vertically spaced and outwardly opening bracket means provided on said vertical members in opposed relation from said connecting means, said bracket means on one unit being longitudinally aligned with corresponding bracket means on the other of said units, the respective aligned bracket means on said frame units being adapted to support trench cribbing members assembled thereto at ground level, said frame units further including means whereby the section of trench cribbing may be transported and set into position within a trench.

2. The invention of claim 1 wherein the means connecting the vertical members of each frame unitconstitutes an adjustable jack screw providing means to adjustthe space between said members in accordance with the trench width and further providing means for moving the vertical members inwardly to withdraw the frame unit after the cribbing section is set in place within the trench.

3. A method of constructing and setting a section of trench cribbing for shoring up the walls of a trench, comprising placing separable frame units in longitudinally spaced and aligned relation at ground level, said units having outwardly opening bracket means respectively aligned horizontally adapted to receive and support outwardly of said units a plurality of longitudinal stringers in transversely spaced and aligned relation, assembling longitudinal stringers of a length sufficient to span the distance between the frame units to the respectively aligned bracket means of said units, securing cross-braces between the transversely spaced stringers and vertical sheathing to the outer surface of said stringers to complete the assembly of the cribbing section to the frame units, transferring the frame units together with the assembled cribbing section from ground level to the trench and setting same into position within the trench with the sheathing disposed adjacent the trench walls, and collapsing and removing the frame units from the cribbing section and trench for use in constructing and setting a subsequent section of trench cribbing.

4. A method of construction and setting a section of trench cribbing for shoring up the opposed walls of a trench, comprising providing a section of trench cribbing having opposed walls, providing a cribbing support frame structure having spaced side members to receive the corresponding walls of said cribbing and having collapsible spacing members rigidly supporting said side members in spaced relation, assembling onto said frame structure at ground level outside of the trench the opposed walls of said section of trench cribbing, transferring the frame structure together with the assembled cribbing section from the assembly location outside of the trench and setting the same into position within the trench with the cribbing walls adjacent the opposed trench walls, collapsing the frame structure with respect to the set cribbing section, and removing the collapsed frame structure from the trench for use in constructing and setting a subsequent section of trench cribbing.

References Cited in the file of this patent UNITED STATES PATENTS 655,532 Washington Aug. 7, 1900 841,773 Fitzgerald Jan. 22, 1907 1,775,060 Bauer Sept. 2, 1930 2,482,367 Ravers Sept. 20, 1949 FOREIGN PATENTS 225,065 Great Britain 1924 

